One's impressions of sounds are a personal thing. Having said that the G37 is frequently criticized for its engine note. Below is from Edmunds....:

"Driving Impressions

The 3.7-liter V6 found in the 2013 Infiniti G sedan is quite strong and provides quick acceleration. While we're not fans of the coarse noise the engine makes in the G37 at higher engine speeds, for the money, you can't beat it in this class."